On August 24, the Massachusetts Department of Public Utilities issued a net metering order which addresses the definition of “facility” and “unit” for both private and public net energy metering facilities in the state, based on 2010 statutory changes. Among other things, this 2010 law, Chapter 359, required the DPU to create two net metering caps, one for municipalities and other governmental units in addition to a separate private cap. The DPU requested comments on these issues over the past summer, resulting in this order.

Highlights from the order:

– The private system limit is 2 MW; any private renewable energy facility exceeding 2 MW is not eligible for NEM.

– The public system limit is 10 MW and is a bit more flexible based on “units” comprising the “facility.” Basically, the MW cap that applies to private “facilities” applies to public “units,” such that a Class III public facility could have several 2 MW units up to a total of 10 MW, but a private facility would only be allowed up to 2 MW.

– A “Unit” for wind is a turbine; for agricultural digesters a single piece of generating equipment; and for solar “an inverter, provided that a solar project proponent may self-designate whether a project is a Class II or Class III NEM facility as long as the project includes the minimum number of inverters required to qualify as such facility” (intended to allow flexibility for various technological developments and innovations, e.g., micro-inverters)

– A “Facility” is defined by a “three-factor approach” — for any technology, it’s “the energy generating equipment associated with a single parcel of land, interconnected with the electric distribution system at a single point, behind a single meter.”

– These rules are effective immediately (as of August 24, 2012) with two exemptions — facilities that are already operating or in an “advanced stage of development.”